diff --git a/Source/cmSetCommand.cxx b/Source/cmSetCommand.cxx
index ed36dc539..1d70ad6e4 100644
--- a/Source/cmSetCommand.cxx
+++ b/Source/cmSetCommand.cxx
@@ -59,7 +59,7 @@ bool cmSetCommand
   // SET (VAR) // Removes the definition of VAR.
   if (args.size() == 1)
     {
-    this->Makefile->RemoveDefinition(args[0]);
+    this->Makefile->RemoveDefinition(variable);
     return true;
     }
   // SET (VAR PARENT_SCOPE) // Removes the definition of VAR